The present invention relates to a fuel-filtering device attached to a fuel suction port located in a fuel tank.
A fuel pump transfers fuel in a fuel tank to an internal combustion engine via a suction pipe provided inside the fuel tank. In order to remove water from the transferred fuel as well as to prevent foreign materials from being sent to the fuel pump, a filter is attached to a fuel suction port of the suction pipe.
This type of filter has been disclosed in Japanese Patent Publication (KOKAI) No. 2000-246026. The filter is formed in a bag shape, and has an outer layer made of an extruded mesh and an inner layer made of a non-woven fabric. Also, a spacing member is provided inside the filter for maintaining an inflated bag shape of the filter.
According to the filter described above, water can be separated by the outer layer to a certain degree, and the inner layer can remove the foreign materials, such as dust, fiber pieces, peeled plating pieces, and solder grounds.
It is known that water can be separated more efficiently as a mesh of the filter becomes finer. However, in the conventional filter, there is a limit to make a mesh finer since the outer layer is made of the extruded mesh.
Also, a lower section of the filter contacts an inner surface at a lower section of a fuel tank. Therefore, when the fuel tank expands due to a change in an internal pressure, the spacing member is pressed and moved. When the spacing member is moved, the spacing member slides and contacts the inner layer.
In the conventional filter, the inner layer tends to be worn out with time. Also, small pieces may be fallen off from the filter due to the sliding contact, and these pieces may be sent to the internal combustion engine from the fuel suction port.
Accordingly, an object of the invention is to provide a fuel-filtering device with improved water separation efficiency.
Another object of the invention is to provide a fuel-filtering device with a spacing member for maintaining an inflated bag shape, and small pieces fallen off from the filter due to the sliding contact between the spacing member and the fuel tank are eliminated.
Further objects and advantages of the invention will be apparent from the following description of the invention.